NORTHAMPTON — When former state Sen. Michael R. Knapik stepped down in August to take a position at Westfield State University, it triggered a special election to decide his successor.

Democrat David K. Bartley and Republican Donald F. Humason emerged the victors after primary elections in October, and will face off in Tuesday’s special election.

The winner will represent Easthampton, Southampton, Westfield, Holyoke, Agawam, Granville, Montgomery, Russell, Southwick, Tolland and part of Chicopee in the state Senate.

Bartley, 48, an attorney and first-term Holyoke city councilor, is a member of a well-known political family. His father, David M. Bartley, was speaker of the state House of Representatives from 1969 to 1975, and also served as president of Holyoke Community College.

Humason, a state representative from Westfield, has a connection to the Senate seat, having worked as Knapik’s chief of staff and legislative aide.

Both candidates support an area casino and said they want the state’s local aid funding formula adjusted to be more equitable to western Massachusetts cities and towns.

Bartley said he wants to see existing tax revenues used more effectively to shore up infrastructure and support public education rather than add any new taxes to make up shortfalls.

Humason is in favor of extending tax incentives to businesses so they will operate here and help spur the local economy.

Profiles of both candidates and their stands on some of the issues appear on this page.

David K. Bartley

Age: 48

Address: 25 Hillcrest Ave., Holyoke

Occupation: Holyoke City Councilor, attorney, former government auditor

When the opportunity to run for the seat vacated by Knapik arose, Bartley said he did not take long to decide to run.

“Sen. Knapik’s departure caught me by surprise and I’m sure it caught plenty of people by surprise,” Bartley said. “There wasn’t much time to dwell on the matter. It was either make a decision, one way or the other, and I had to do it quickly.”

Bartley, who is a first-term Holyoke city councilor and practicing attorney, worked as a state auditor from 1996 to 2013.

“What I offer is experience in following the money,” he said. “When the money gets in the hands of certain government agencies and plenty of vendors, it doesn’t necessarily get to the targeted population.”

Those “targeted populations” include area homeless and poor people who would benefit more from investing in options such as low-cost housing rather than being put up in hotels and motels, he said.

“When you look at a budget of $34 billion, you have priorities, you direct resources to the priorities but you need to have auditors and other officials in place that track the money and make sure we’re doing it right. And if we’re not, those dollars need to go away and be used more efficiently,” Bartley said.

Bartley believes taxpayers get frustrated when their money doesn’t seem to be addressing social problems such as poverty and homelessness — and yet their taxes go up.

“We don’t want to have or perpetuate the welfare myth by having folks live in the welfare motels — that is a disaster, continues to be a disaster,” he said.

“We have to look at building public housing smartly, not having to spend hundreds of thousands of dollars on a single-unit rehab, which I have seen in my career,” he said.

Bartley said state taxpayers already contribute plenty of money to the system, especially homeowners, but oftentimes that money is used ineffectively.

“The money that we have has to be used wisely. That is getting the money out of Boston and bringing it back to the cities and towns where our local leaders who know the needs of its citizens best can use those dollars effectively and efficiently,” he said.

“When we increase local aid, we alleviate some of the burden on the property taxes. Because when local aid goes away, the municipal government, which is primarily based on the property tax, goes right back to the homeowner,” Bartley said.

Bartley said he’s in favor of reworking the formula for how much local aid reaches cities and towns. He said the current formula relies too heavily on population numbers and doesn’t take into account poverty levels.

“It’s got to change because we don’t have the population out here to compete with that, but we have the poverty. We have the need, we have the homelessness, we have people living in motels and hotels,” he said.

“We have the low graduation rates, we have the high teenage pregnancy rates, we’ve got societal, social needs that cannot be realistically supported by property tax dollars,” Bartley said.

Bartley said he is hopeful that when state Sen. Stanley Rosenberg, D-Amherst, takes over as Senate president, as is expected in 2015, it will give western Massachusetts a powerful voice to influence some of those changes to help support the region.

“He’s the first western Massachusetts political leader of that stature since my father was a speaker,” Bartley said. “We haven’t seen the likes of that in at least a couple of generations.”

Bartley’s father, David M. Bartley, left the House in 1975.

Bartley said he’s in favor of a casino coming to the area on the condition that the revenues generated benefit western Massachusetts. “My personal preference is that, yes, we should have a casino. My main concern is what happens with the revenues generated from the casino,” he said. “That has got be a legislator’s concern. I want to make sure those revenues come back to western Mass. so we can use those tax dollars wisely and efficiently.”

Bartley also said he wants to see existing opportunities in the area promoted and developed, such as the manufacturing industry.

“There are literally job openings in manufacturing,” he said. “We’ve got to get educated students coming out of the technical and vocational schools. That’s something that a state senator who’s in touch with business folks as well as government officials can do — promote that region and tell that story.”

Bartley is unmarried and has no children.

Donald F. Humason

Age: 46

Address: 90 Stony Lane, Westfield

Occupation: Republican state representative, elected in 2002

Donald Humason said his experience as a state representative and his time as former state Sen. Michael Knapik’s legislative aide and chief of staff makes him the best candidate to fill the vacated seat.

“I’ve made my experience in the Legislature a cornerstone of my campaign because it’s something that does differentiate me from my opponent,” Humason said. “Having that historical perspective of who’s who in the Pioneer Valley in politics is helpful because as a candidate with experience in the business, it’s nice to have contacts on both sides of the aisle.”

Humason said the recent government shutdown and fiscal debate has tarnished the Republican label, but only for those who already have an ax to grind with the party.

“I’m a Republican, and my opponent has done everything he can to make sure people know that and I appreciate it. I don’t think that’s necessarily a bad thing,” he said. “Especially when I have a record of my own, accomplishments and a reputation of my own.”

Humason said he does not believe the gridlock common in Washington politics is a problem at the Statehouse.

“The way we do things in Boston is very different from the way things are done in Washington, D.C.,” he said. “When we don’t agree with each other in Boston, we still pass a budget. When Republicans and Democrats don’t agree in Boston, we don’t go into debt and we don’t shut down the government.”

“As much as my opponent has tried to paint me as part of that, that’s ridiculous. I don’t work in Washington, I work in Boston. I’m elected locally, not nationally,” he said. Like his opponent, Humason agrees the formula to provide local aid to communities is skewed to the detriment of western Massachusetts communities. He said inaction on the part of Democrats is to blame.

“Republicans and Democrats have always been talking about how we feel that the local aid formula doesn’t help us, because we’re smaller communities. We don’t have the population, we don’t have some of the metrics that they have in Boston,” he said. “So it’s very frustrating for me to hear that my opponent is complaining about local aid and how we get treated shabbily in western Mass. because it’s his party that dominates that debate and dominates that process in Boston. If the Democrats who control the corner office and legislative branches wanted local aid formulas to change, they would have changed them.”

Humason said legislation has been filed that would set a “floor” for state aid, so communities would be able to construct their budgets around a minimum amount of aid.

“Then, if we give them more, that’s great, but at least they don’t go below that floor,” he said. “My opponent is correct: Local aid is a huge issue. Unfortunately his party is part of the problem, not the solution. And when he says he’s going to go to Boston and change how local aid is distributed, I think he’s being disingenuous because he’s going to be bucking up against his own party leadership to do that.”

Humason said he supports bringing casino gaming to western Massachusetts.

“I voted in favor of casino gaming,” he said. “I voted for that primarily because I didn’t have a huge opposition to it. I wasn’t a drastic supporter, nor was I a drastic opponent.

“I felt like it was one of several tools we could use for economic development. It was one of several ways to keep Massachusetts dollars from running down to Connecticut,” he added. “I certainly didn’t see it as the end-all and be-all to our economic woes.”

He objected to the proposed state tax on tech services, noting that businesses that would have been affected by the change may have halted plans to expand or scrapped plans to set up shop in the state based on the news they may be taxed at a higher rate when doing business here.

“Even by talking about it, we did ourselves harm,” he said. “I think it will take a little while for that industry to recover.”